This invention relates to a molded plastic dental tray employed to obtain dental impressions.
A typical dental tray for obtaining impressions is disclosed in U.S. Pat. No. 2,583,170 to E. H. Getz, and this device has been commercialized for many years as a double bite wing tray in metal form. The Getz tray includes buccal and lingual walls joined by a connecting bar, each tray being manufactured in sections which are perforated by machining and then joined together. The manufacturing operation is expensive since each tray must be perforated and then brazed together in a joining operation. Furthermore, all edges must be smoothed to eliminate any projecting metal portions which could injure a patient's mouth while in use. Overall, the Getz type tray is an expensive device.
If it were possible to produce a double bite wing tray in a molded plastic form, a considerable saving could be effected both in terms of a simpler mold and also with a faster production run. However, forming a large number of perforations in a molded plastic dental tray which could perform the same function as the Getz type tray is costly in terms of mold expenses. Nevertheless, a molded plastic dental tray which is equivalent to the Getz type metal tray is desired. Preferably, such a molded plastic dental tray would be formed using standard injection molding techniques to attain high production rates and a corresponding decrease in unit costs.
In addition to the Getz tray, many other forms of perforated dental impression trays have been used in the past, the perforations functioning to lock an impression support material thereto. However, it is physically difficult to clean the impression material from the perforations, and if a cleaning compound is employed, this represents an added expense and generally requires an extended immersion period.